1. Field of the Invention
The present invention relates to a dental handpiece structure, and more particularly to the dental handpiece structure capable of improving the interference of airflow field in a turbine chamber, and providing a secondary impact on turbine vanes to increase the airflow field efficiency to enhance a cutting force.
2. Description of the Related Art
With reference to FIG. 6 for a conventional dental hand-piece, the dental handpiece comprises a head 91, a turbine chamber 92 formed in the head 91 and having an upward opening, a rotor axially installed at the turbine chamber 92 and rotatable freely, and a screwing cap 94 locked onto the opening of the turbine chamber 92, wherein a burr 931 such as a molar knife or a drill is extended outwardly from an end of the rotor 93, and a transmission element 932 composed of a plurality of turbine vanes is formed at a middle section position of the rotor 93, so that when a high-pressure air enters into the turbine chamber 92, the gas can push the turbine vanes of the transmission element 932 to drive the rotor 93 to rotate in a circumferential direction of the rotor 93.
In the actual use of the conventional dental hand-piece, the high-pressure air is guided towards the breach between two adjacent turbine vanes to the outside, after the high-pressure air entering into the turbine chamber 92 pushes the turbine vanes of the transmission element 932. Since an end surface of the screwing cap 94 facing the turbine chamber 92 is substantially in a flat shape without any design of guiding and collecting the high-pressure air, therefore the upwardly guided high-pressure air may create a turbulence (as indicated by the arrow in the figure) easily when the gas impacts the end surface at the bottom of the screwing cap 94, and an interference of the airflow field in the turbine chamber 92 is formed to result in the disadvantages of an increased rotating resistance and a decreased torque. In addition, the gas in the turbine chamber 92 of the conventional dental handpiece may be discharged quickly, so that the effects of producing a secondary impact of the turbine vanes by the high-pressure air or improving the work efficiency of the airflow field cannot be achieved.